This invention relates to a crane assembly, and more particularly to hoisting apparatus for use on an existing structure.
Hoisting cranes comprising assemblies of masts, booms and cables are of course well known. One example is shown in U.S. Pat. No. Re. 20,551 to W. E. Rouse for Mooring and Hoisting Apparatus on a ship for lifting objects from the surface of the sea.
The principal object of the present invention is to provide a crane assembly of minimum weight.